The Biomechanics of the Golf Swing: Understanding and Preventing Hip and Lumbar Spine Injuries
- oliviaohmer
- Apr 7
- 6 min read
Golf is often perceived as a low-impact sport, yet hip and lumbar spine injuries are becoming increasingly common. The sport’s growing popularity and the misconception that it is injury-free have contributed to rising injury rates in recent years. Low back injuries are the most prevalent, accounting for up to 50% of all injuries among golfers, while hip injuries affect approximately 19% of golfers.
Through an examination of the biomechanics involved in the golf swing, this research will delve into the physical aspects of the sports, investigate the connection between the golf swing and injuries, and evaluate how modifications such as the Minimalist Golf Swing (MGS) can mitigate these risks.
First, let me share my background. I am a graduating senior at Adrian College, set to graduate with honors in Biology and Public Health. My long-term aspiration is to become a Physician’s Assistant (PA) and dedicate myself to delivering the highest quality of care to patients. In addition to my academic and career pursuits, I am an NCAA Division III college golfer and have been playing the sport since the age of eight. During my sophomore year, I was honored as MVP for the MIAA conference, set a school record with a score of 73, and have won six collegiate tournaments individually. My passion for science, health, and golf has led me to explore the often overlooked injuries that golfers experience. Last semester, I completed an honors project in Human Anatomy to deepen my understanding of the human body’s foundations and its connection to overuse injuries in golfers. Building on this knowledge, I have expanded my research and developed a proposal to further analyze the biomechanics of the golf swing, aiming to produce a comprehensive literature review.
The golf swing relies on torque and angular momentum to generate speed and power. A 2005 study by Nesbit and Serrano examined the work and power involved in the golf swing, focusing on the contributions of various joints. They used computer models and motion data from golfers to analyze the swing mechanics of four amateur golfers with different skill levels, body types and swing styles. Their research revealed that the lumbar and thoracic spine, and hip joints contribute 68.7-72.2% of the total work in the golf swing, while the shoulder and arm joints account for 24.3-28%. The leg joints contribute only 3.3-3.8%.
Focusing on the hip, a 2009 study by Heather Gulgin examined 15 healthy female golfers using high-speed 3D videography. All participants were right-handed and had no recent injuries. Gulgin found that the lead hip (left hip) experiences significantly higher internal rotational velocity during the downswing compared to the trail hip’s external rotational velocity. This phenomenon, occurring in a closed kinetic chain known as the “danger zone”, can create torsion on the hip, predisposing it to injury. The rotational velocity stresses the hip joint, potentially risking acetabular labrum tears, even without exceeding the normal range of motion.
The Crunch Factor is a technique in the golf swing that may contribute to spine injuries. It highlights the stress on the thoracic and lumbar spine during the downswing and follow-through phases. The two major components are:
1. Lateral Trunk Flexion (sideways bending of the torso during the swing)
2. Axial Trunk Rotational Velocity (speed at which the torso rotates around the spine to generate power)
A high Crunch Factor indicates a more powerful swing, while a lower Crunch Factor suggests a less powerful swing. Researchers use the Crunch Factor to understand the kinematics of the golf swing and develop strategies to prevent injuries.
In 2016, Christopher Joyce from the University of Notre Dame Australia studied the Crunch Factor’s relationship with trunk movements and swing/launch parameters in 20 professional and amateur male golfers. He found that a higher Crunch Factor correlates with increased club head and ball speed, enhancing drive performance. However, this also raises the risk of low back injury due to the shear and compressive forces from the closed kinetic chain activity with rotation and lateral bending.
In 2013, researchers Cole and Grimshaw studied the Crunch Factor’s impact on low back injuries by comparing 12 male golfers with low back pain to 15 without. Surprisingly, both groups showed an increase in the Crunch Factor from the downswing to the follow-through. Despite initial beliefs, the study found no significant difference in lateral flexion angle and axial rotational velocity between golfers with and without low back pain. The researchers suggest that golfers with low back pain might adjust their swing to reduce pain, indicating that the Crunch Factor may not predict low back pain.
Another factor in golf performance and injuries is trunk muscle activation. Cole and Grimshaw examined the trunk and abdominal muscles in 12 male golfers with low back pain and 18 without, divided by skill level. Using Electromyography (EMG) analysis, they found that less skilled golfers with low back pain had greater muscle activity at the top of the backswing/start of downswing. Skilled golfers with low back pain showed higher external oblique activity at these points and at impact. The increased erector spinae activity in less skilled golfers suggests it stabilizes the spine, reducing external oblique activity.
Cole and Grimshaw also found that skilled golfers with low back pain showed muscle activation patterns in the erector spinae before starting the backswing. The erector spinae, a group of muscles and tendons along the spine, are responsible for extending and rotating the spine and maintaining upright posture. This pattern helps stabilize the spine due to weaker deeper muscles, such as the multifidus muscle, which stabilizes vertebrae and prevents shear forces and excessive strain on the lumbar spine. If the erector spinae compensate for the multifidus, the same level of protection may not be provided, increasing the risk of injuries like disc herniation or strains.
While injury risk among golfers is prevalent, there are a few preventative techniques for hip and lumbar spine injuries. In 2015, Dale and Brumitt studied 13 skilled golfers using the modern one-plane golf swing technique, comparing full and shortened backswings. They found that the shorted swing reduced vertebral compression force without significantly affecting club head velocity, shot distance, or accuracy; potentially reducing spine injury risk.
Similarly, the Minimalist Golf Swing (MGS) also uses a single-plane technique to minimize unnecessary movements and reduce joint stress. Differences from the traditional swing include a centered ball position, minimal knee and hip bend, and reduced torso rotation. This leads to less hip rotation, compression forces, and lateral bending. Kanwar’s study on the MGS found it reduced lumbar spine transverse plane range of motion by 18.3%, and lead hip and knee range of motion by about 40%. The MGS also resulted in a shallower club approach, more in-to-out club path, and slightly slower club speed. Overall, the MGS reduces joint range of motion and injury risk, allowing golfers to play more injury-free without compromising performance.
The biomechanics of the golf swing, along with the numerous critical factors influencing performance, make injury prevention a complex challenge. However, by integrating these insights, golfers and coaches can create more effective training and technique programs to enhance performance and reduce the risk of injuries.
References:
Cole, M. H., & Grimshaw, P. N. (2008). Electromyography of the trunk and abdominal muscles in golfers with and without low back pain. Journal of science and medicine in sport, 11(2), 174–181. https://doi.org/10.1016/j.jsams.2007.02.006
Cole, M.H., & Grimshaw, P. N. (2008). Trunk muscle onset and cessation in golfers with and without low back pain. Journal of Biomechanics, 41(13), 2829–2833. https://doi.org/10.1016/j.jbiomech.2008.07.004
Cole, M. H., & Grimshaw, P. N. (2014). The crunch factor’s role in golf-related low back pain. The Spine Journal, 14(5), 799–807. https://doi.org/10.1016/j.spinee.2013.09.019
Dale, R. B., & Brumitt, J. (2016). Spine biomechanics associated with the shortened, modern one-plane golf swing. Sports Biomechanics, 15(2), 198–206. https://doi.org/10.1080/14763141.2016.1159723
Gulgin, H., & Armstrong, C. (2006b). Hip rotational velocities during the full golf swing. Medicine & Science in Sports & Exercise, 38(Supplement). https://doi.org/10.1249/00005768-200605001-02539
Joyce, C., Chivers, P., Sato, K., & Burnett, A. (2016). Multi-segment trunk models used to investigate the crunch factor in golf and their relationship with selected swing and launch parameters. Journal of Sports Sciences, 34(20), 1970–1975. https://doi.org/10.1080/02640414.2016.1149600
Kanwar, K. D., Cannon, J., Nichols, D. L., Salem, G. J., & Mann, M. D. (2021). Injury risk-factor differences between two golf swing styles: a biomechanical analysis of the lumbar spine, hip and knee. Sports Biomechanics, 23(10), 1504–1525. https://doi.org/10.1080/14763141.2021.1945672
Nesbit, S. M., & Serrano, M. (2005). Work and power analysis of the golf swing. Journal of sports science & medicine, 4(4), 520–533.